PEER simplified lipid guideline 2023 update: Prevention and management of cardiovascular disease in primary care.

OBJECTIVE: To update the 2015 clinical practice guideline and provide a simplified approach to lipid management in the prevention of cardiovascular disease (CVD) for primary care. METHODS: Following the Institute of Medicine's Clinical Practice Guidelines We Can Trust, a multidisciplinary, pan-Canadian guideline panel was formed. This panel was represented by primary care providers, free from conflicts of interest with industry, and included the patient perspective. A separate scientific evidence team performed evidence reviews on statins, ezetimibe, proprotein convertase subtilisin-kexin type 9 inhibitors, fibrates, bile acid sequestrants, niacin, and omega-3 supplements (docosahexaenoic acid with eicosapentaenoic acid [EPA] or EPA ethyl ester alone [icosapent]), as well as on 11 supplemental questions. Recommendations were finalized by the guideline panel through use of the Grading of Recommendations Assessment, Development and Evaluation methodology. RECOMMENDATIONS: All recommendations are presented in a patient-centred manner designed with the needs of family physicians and other primary care providers in mind. Many recommendations are similar to those published in 2015. Statins remain first-line therapy for both primary and secondary CVD prevention, and the Mediterranean diet and physical activity are recommended to reduce cardiovascular risk (primary and secondary prevention). The guideline panel recommended against using lipoprotein a, apolipoprotein B, or coronary artery calcium levels when assessing cardiovascular risk, and recommended against targeting specific lipid levels. The team also reviewed new evidence pertaining to omega-3 fatty acids (including EPA ethyl ester [icosapent]) and proprotein convertase subtilisin-kexin type 9 inhibitors, and outlined when to engage in informed shared decision making with patients on interventions to lower cardiovascular risk. CONCLUSION: These updated evidence-based guidelines provide a simplified approach to lipid management for the prevention and management of CVD. These guidelines were created by and for primary health care professionals and their patients.

Lipid-lowering therapies for cardiovascular disease prevention and management in primary care: PEER umbrella systematic review of systematic reviews.

OBJECTIVE: To assess the benefits and harms of lipid-lowering therapies used to prevent or manage cardiovascular disease including bile acid sequestrants (BAS), ezetimibe, fibrates, niacin, omega-3 supplements, proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, and statins. DATA SOURCES: MEDLINE, the Cochrane Database of Systematic Reviews, and a grey literature search. STUDY SELECTION: Systematic reviews of randomized controlled trials published between January 2017 and March 2022 looking at statins, ezetimibe, PCSK9 inhibitors, fibrates, BAS, niacin, and omega-3 supplements for preventing cardiovascular outcomes were selected. Outcomes of interest included major adverse cardiovascular events (MACE), cardiovascular mortality, all-cause mortality, and adverse events. SYNTHESIS: A total of 76 systematic reviews were included. Four randomized controlled trials were also included for BAS because no efficacy systematic review was identified. Statins significantly reduced MACE (6 systematic reviews; median risk ratio [RR]=0.74; interquartile range [IQR]=0.71 to 0.76), cardiovascular mortality (7 systematic reviews; median RR=0.85, IQR=0.83 to 0.86), and all-cause mortality (8 systematic reviews; median RR=0.91, IQR=0.88 to 0.92). Major adverse cardiovascular events were also significantly reduced by ezetimibe (3 systematic reviews; median RR=0.93, IQR=0.93 to 0.94), PCSK9 inhibitors (14 systematic reviews; median RR=0.84, IQR=0.83 to 0.87), and fibrates (2 systematic reviews; mean RR=0.86), but these interventions had no effect on cardiovascular or all-cause mortality. Fibrates had no effect on any cardiovascular outcomes when added to a statin. Omega-3 combination supplements had no effect on MACE or all-cause mortality but significantly reduced cardiovascular mortality (5 systematic reviews; median RR=0.93, IQR=0.93 to 0.94). Eicosapentaenoic acid ethyl ester alone significantly reduced MACE (1 systematic review, RR=0.78) and cardiovascular mortality (2 systematic reviews; RRs of 0.82 and 0.82). In primary cardiovascular prevention, only statins showed consistent benefits on MACE (6 systematic reviews; median RR=0.75, IQR=0.73 to 0.78), cardiovascularall-cause mortality (7 systematic reviews, median RR=0.83, IQR=0.81 to 0.90), and all-cause mortality (8 systematic reviews; median RR=0.91, IQR=0.87 to 0.91). CONCLUSION: Statins have the most consistent evidence for the prevention of cardiovascular complications with a relative risk reduction of about 25% for MACE and 10% to 15% for mortality. The addition of ezetimibe, a PCSK9 inhibitor, or eicosapentaenoic acid ethyl ester to a statin provides additional MACE risk reduction but has no effect on all-cause mortality.

Lignes directrices simplifiées de PEER sur les lipides : actualisation 2023: Prévention et prise en charge des maladies cardiovasculaires en soins primaires.

OBJECTIF: Actualiser le guide de pratique clinique de 2015 et présenter une approche simplifiée de la prise en charge des lipides dans la prévention des maladies cardiovasculaires (MCV) en première ligne. MÉTHODES: Conformément aux recommandations de l'Institute of Medicine dans Clinical Practice Guidelines We Can Trust, un panel pancanadien d'experts multidisciplinaires en lignes directrices a été formé. Ce panel était représentatif des cliniciens en soins primaires, libre de tout conflit d'intérêts avec l'industrie, et il tenait compte des points de vue des patients. Une équipe distincte, responsable des données probantes scientifiques, a passé en revue l'information sur les statines, l'ézétimibe, les inhibiteurs de la proprotéine convertase subtilisine-kexine de type 9, les fibrates, les chélateurs des acides biliaires, la niacine et les suppléments d'omega-3 (acide docosahexaénoïque avec acide eicosapentaénoïque [EPA] ou ester éthylique de l'EPA seul [icosapent]), ainsi que sur la réponse à 11 questions supplémentaires. Le panel des lignes directrices a finalisé les recommandations en utilisant la méthodologie GRADE (Grading of Recommendations Assessment, Development and Evaluation). RECOMMANDATIONS: Toutes les recommandations sont présentées de manière à être centrées sur le patient et conçues en ayant à l'esprit les besoins des médecins de famille et des autres cliniciens des soins primaires. De nombreuses recommandations sont semblables à celles publiées en 2015. Les statines demeurent le traitement de première intention pour la prévention tant primaire que secondaire des MCV, et le régime méditerranéen et l'activité physique sont recommandés pour réduire le risque cardiovasculaire (en prévention primaire et secondaire). Le panel des lignes directrices a recommandé de ne pas utiliser le dosage des lipoprotéines a, des apolipoprotéines B ou le score calcique coronarien (SCC) dans l'évaluation du risque cardiovasculaire, et de ne pas cibler de seuils précis de taux lipidiques. L'équipe a aussi passé en revue de nouvelles données concernant les acides gras omega-3 (y compris l'ester éthylique d'EAP [icosapent]) et les inhibiteurs de la proprotéine convertase subtilisine-kexine de type 9, et a précisé les moments où il convient de procéder à une prise de décision partagée avec les patients sur les interventions pour diminuer le risque cardiovasculaire. CONCLUSION: Ces lignes directrices actualisées et fondées sur des données probantes présentent une approche simplifiée de la prise en charge des lipides pour la prévention et le traitement des MCV. Ce guide de pratique clinique a été conçu par et pour des professionnels de la santé en soins primaires et leurs patients.

Top 2020 studies relevant to primary care: From the PEER team.

OBJECTIVE: To summarize high-quality studies for 10 topics from 2020 that have strong relevance to primary care practice. SELECTING THE EVIDENCE: Study selection involved routine literature surveillance by a group of primary health care professionals. This included screening abstracts of high-impact journals and EvidenceAlerts, as well as searching the American College of Physicians Journal Club. MAIN MESSAGE: Topics of the 2020 articles most likely to affect primary care practice included whether antibiotic prophylaxis reduces maternal infections following operative vaginal birth; which second-line agent after metformin reduces cardiovascular outcomes for patients with diabetes; whether gabapentin is effective for alcohol use disorder; whether compression stockings prevent recurrent cellulitis; guideline recommendations for management of dyslipidemia to reduce cardiovascular risk; whether intermittent fasting is superior to consistent mealtimes for weight loss; whether vitamin C added to iron supplementation increases hemoglobin more than iron alone; whether antacid-lidocaine combinations are superior to antacid alone for epigastric pain; whether dapagliflozin improves renal and cardiovascular outcomes in chronic kidney disease; and whether empagliflozin improves cardiovascular outcomes in patients with heart failure. Five "runner-up" studies are also briefly reviewed. CONCLUSION: Research from 2020 produced several high-quality studies in diabetes and cardiovascular disease, but also included a variety of other conditions relevant to primary care such as vaginal operative births, alcohol use disorder, weight loss, and chronic leg edema.

Principales études pertinentes aux soins primaires en 2020: De l'équipe du groupe PEER.

OBJECTIF: Faire la synthèse d'études de grande qualité sur 10 sujets, publiées en 2020, qui sont d'une grande pertinence pour la pratique des soins primaires. SÉLECTION DES DONNÉES PROBANTES: La sélection des études s'est faite à la suite d'une surveillance systématique de la littérature scientifique par un groupe de professionnels de la santé en soins primaires. Les résumés de revues à fort impact et les EvidenceAlerts ont été dépouillés, de même que l'American College of Physicians Journal Club. MESSAGE PRINCIPAL: Au nombre des articles en 2020 qui influenceront fort probablement la pratique des soins primaires figurent ceux portant sur les questions suivantes : l'antibioprophylaxie réduit-elle les infections maternelles à la suite d'un accouchement vaginal opératoire? Quel agent de deuxième intention après la metformine réduit les risques cardiovasculaires chez les patients diabétiques? La gabapentine est-elle efficace pour les troubles liés à la consommation d'alcool? Les bas de contention préviennent-ils la cellulite récurrente? Le jeûne intermittent est-il supérieur à des repas à heures régulières pour perdre du poids? La vitamine C ajoutée aux suppléments de fer augmente-t-elle plus l'hémoglobine que le fer seul? Les combinaisons d'antiacides et de lidocaïne sont-elles supérieures aux antiacides seuls pour la douleur épigastrique? La dapagliflozine améliore-t-elle les issues rénales et cardiovasculaires dans les cas de néphropathie chronique? L'empagliflozine améliore-t-elle les résultats cardiovasculaires chez les patients souffrant d'insuffisance cardiaque? Cinq sujets d'intérêt additionnels sont aussi passés brièvement en revue. CONCLUSION: La recherche a produit en 2020 plusieurs études de grande qualité sur le diabète et les maladies cardiovasculaires, de même que sur divers autres problèmes pertinents en soins primaires, comme les accouchements vaginaux opératoires, les troubles liés à la consommation d'alcool, la perte pondérale et l'œdème chronique des jambes.

Magnesium for skeletal muscle cramps.

BACKGROUND: Skeletal muscle cramps are common and often occur in association with pregnancy, advanced age, exercise or motor neuron disorders (such as amyotrophic lateral sclerosis). Typically, such cramps have no obvious underlying pathology, and so are termed idiopathic. Magnesium supplements are marketed for the prophylaxis of cramps but the efficacy of magnesium for this purpose remains unclear. This is an update of a Cochrane Review first published in 2012, and performed to identify and incorporate more recent studies. OBJECTIVES: To assess the effects of magnesium supplementation compared to no treatment, placebo control or other cramp therapies in people with skeletal muscle cramps.   SEARCH METHODS: On 9 September 2019, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, LILACS, CINAHL Plus, AMED, and SPORTDiscus. We also searched WHO-ICTRP and ClinicalTrials.gov for registered trials that might be ongoing or unpublished, and ISI Web of Science for studies citing the studies included in this review. SELECTION CRITERIA: Randomized controlled trials (RCTs) of magnesium supplementation (in any form) to prevent skeletal muscle cramps in any patient group (i.e. all clinical presentations of cramp). We considered comparisons of magnesium with no treatment, placebo control, or other therapy. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion and extracted data. Two review authors assessed risk of bias. We attempted to contact all study authors when questions arose and obtained participant-level data for four of the included trials, one of which was unpublished. We collected all data on adverse effects from the included RCTs. MAIN RESULTS: We identified 11 trials (nine parallel-group, two cross-over) enrolling a total of 735 individuals, amongst whom 118 cross-over participants additionally served as their own controls. Five trials enrolled women with pregnancy-associated leg cramps (408 participants) and five trials enrolled people with idiopathic cramps (271 participants, with 118 additionally crossed over to control). Another study enrolled 29 people with liver cirrhosis, only some of whom suffered muscle cramps. All trials provided magnesium as an oral supplement, except for one trial which provided magnesium as a series of slow intravenous infusions. Nine trials compared magnesium to placebo, one trial compared magnesium to no treatment, calcium carbonate or vitamin B, and another trial compared magnesium to vitamin E or calcium. We judged the single trial in people with liver cirrhosis and all five trials in participants with pregnancy-associated leg cramps to be at high risk of bias. In contrast, we rated the risk of bias high in only one of five trials in participants with idiopathic rest cramps. For idiopathic cramps, largely in older adults (mean age 61.6 to 69.3 years) presumed to have nocturnal leg cramps (the commonest presentation), differences in measures of cramp frequency when comparing magnesium to placebo were small, not statistically significant, and showed minimal heterogeneity (I² = 0% to 12%). This includes the primary endpoint, percentage change from baseline in the number of cramps per week at four weeks (mean difference (MD) -9.59%, 95% confidence interval (CI) -23.14% to 3.97%; 3 studies, 177 participants; moderate-certainty evidence); and the difference in the number of cramps per week at four weeks (MD -0.18 cramps/week, 95% CI -0.84 to 0.49; 5 studies, 307 participants; moderate-certainty evidence). The percentage of individuals experiencing a 25% or better reduction in cramp rate from baseline was also no different (RR 1.04, 95% CI 0.84 to 1.29; 3 studies, 177 participants; high-certainty evidence). Similarly, no statistically significant difference was found at four weeks in measures of cramp intensity or cramp duration. This includes the number of participants rating their cramps as moderate or severe at four weeks (RR 1.33, 95% CI 0.81 to 2.21; 2 studies, 91 participants; moderate-certainty evidence); and the percentage of participants with the majority of cramp durations of one minute or more at four weeks (RR 1.83, 95% CI 0.74 to 4.53, 1 study, 46 participants; low-certainty evidence). We were unable to perform meta-analysis for trials of pregnancy-associated leg cramps. The single study comparing magnesium to no treatment failed to find statistically significant benefit on a three-point ordinal scale of overall treatment efficacy. Of the three trials comparing magnesium to placebo, one found no benefit on frequency or intensity measures, another found benefit for both, and a third reported inconsistent results for frequency that could not be reconciled. The single study in people with liver cirrhosis was small and had limited reporting of cramps, but found no difference in terms of cramp frequency or cramp intensity. Our analysis of adverse events pooled all studies, regardless of the setting in which cramps occurred. Major adverse events (occurring in 2 out of 72 magnesium recipients and 3 out of 68 placebo recipients), and withdrawals due to adverse events, were not significantly different from placebo. However, in the four studies for which it could be determined, more participants experienced minor adverse events in the magnesium group than in the placebo group (RR 1.51, 95% CI 0.98 to 2.33; 4 studies, 254 participants; low-certainty evidence). Overall, oral magnesium was associated with mostly gastrointestinal adverse events (e.g. diarrhoea), experienced by 11% (10% in control) to 37% (14% in control) of participants. AUTHORS' CONCLUSIONS: It is unlikely that magnesium supplementation provides clinically meaningful cramp prophylaxis to older adults experiencing skeletal muscle cramps. In contrast, for those experiencing pregnancy-associated rest cramps the literature is conflicting and further research in this population is needed. We found no RCTs evaluating magnesium for exercise-associated muscle cramps or disease-state-associated muscle cramps (for example amyotrophic lateral sclerosis/motor neuron disease) other than a single small (inconclusive) study in people with liver cirrhosis, only some of whom suffered cramps.

The Effect of Warfarin Administration Time on Anticoagulation Stability (INRange): A Pragmatic Randomized Controlled Trial.

PURPOSE: Without supporting evidence, clinicians commonly recommend that warfarin be taken in the evening. We conducted a randomized controlled trial to evaluate the effect of administration time (morning vs evening) on the stability of warfarin's anticoagulant effect. METHODS: A total of 236 primary care physicians serving 54 western Canadian communities mailed letters of invitation to all their warfarin-using patients. Eligible patients were community-dwelling warfarin users (any indication) with at least 3 months of evening warfarin use and no plans for discontinuation. Participants were randomized (by web-based allocation) to morning vs continued evening warfarin ingestion. We used the Rosendaal method to determine the proportion of time within therapeutic range (TTR) of the international normalized ratio (INR) blood test month 2 to 7 postrandomization vs the 6 months prerandomization. The primary outcome was the percent change in proportion of time outside target INR range (with an a priori minimum clinically important difference of ±20%). All analyses were intention to treat. RESULTS: Between March 8, 2015 and September 30, 2016, we randomized 109 participants to morning and 108 to evening warfarin use. TTR rose from 71.8% to 74.7% in the morning group, and from 72.6% to 75.6% in the evening group, for a change in TTR of 2.9% in the former vs 3.0% in the latter (difference, -0.1%; P = .97; 95% CI for the difference, -6.1% to 5.9%). The difference in percent change in proportion of time outside the therapeutic INR range (obtained via Hodges-Lehmann estimation of the difference in medians) was 4.4% (P = .62; 95% CI for the difference, -17.6% to 27.3%). CONCLUSIONS: Administration time has no statistically significant nor clinically important impact on the stability of warfarin's anticoagulant effect. Patients should take warfarin whenever regular compliance would be easiest.

Top studies relevant to primary care from 2018: From PEER.

OBJECTIVE: To summarize high-quality studies for 10 topics from 2018 that have strong relevance to primary care practice. QUALITY OF EVIDENCE: Study selection involved routine literature surveillance by a group of primary care health professionals. This included screening abstracts of important journals and Evidence Alerts, as well as searching ACP Journal Club. MAIN MESSAGE: Topics of the 2018 articles include whether low-dose acetylsalicylic acid improves health outcomes like cardiovascular disease (CVD); whether a low-carbohydrate diet is better than a low-fat diet for weight loss (and whether genetics matter); whether vaginal estradiol is superior to placebo for vulvovaginal symptoms of menopause; whether opioid management is better than nonopioid management for chronic back or osteoarthritis pain; whether additional water intake will decrease recurrent urinary tract infections; whether omega-3 fatty acids prevent CVD or reduce dry eyes; whether the new drug icosapent improves CVD; whether bath additives help eczema; whether acetaminophen can prevent recurrent febrile seizures; and recommendations for glycemic targets in diabetes based on reviews of evidence and other guidelines. Five "runner-up" studies are also briefly reviewed. CONCLUSION: Research from 2018 produced several high-quality studies in CVD but also spanned the breadth of primary care including pediatrics, women's health, and pain management, among other areas.

Top studies relevant to primary care practice.

OBJECTIVE: To summarize 10 high-quality studies from 2017 that have strong relevance to primary care practice. QUALITY OF EVIDENCE: Study selection involved routine literature surveillance by a group of primary care health professionals. This included screening abstracts of important journals and Evidence Alerts, as well as searching the American College of Physicians Journal Club. MAIN MESSAGE: Topics of the 2017 articles include whether treating subclinical hypothyroidism improves outcomes or symptoms; whether evolocumab reduces cardiovascular disease as well as low-density lipoprotein levels; whether lifestyle interventions reduce medication use in patients with diabetes; whether vitamin D prevents cardiovascular disease, cancer, or upper respiratory tract infections; whether canagliflozin reduces clinical events in patients with diabetes; how corticosteroid injections affect knee osteoarthritis; whether drained abscesses benefit from antibiotic treatment; whether patients with diabetes benefit from bariatric surgery; whether exenatide reduces clinical events in patients with diabetes; and whether tympanostomy tubes affect outcomes in recurrent acute otitis media or chronic otitis media. We provide brief summaries, context where needed, and final recommendations for 10 studies with potential effects on primary care. We also briefly review 5 "runner-up" studies. CONCLUSION: Research from 2017 produced several high-quality studies in diabetes management. These have demonstrated benefit for alternative therapies and offered evidence not previously available. This year's selection of studies also provided information on a variety of conditions and therapies that are, or might become, more common in primary care settings.

Systematic review of systematic reviews for medical cannabinoids: Pain, nausea and vomiting, spasticity, and harms.

OBJECTIVE: To determine the effects of medical cannabinoids on pain, spasticity, and nausea and vomiting, and to identify adverse events. DATA SOURCES: MEDLINE, the Cochrane Database, and the references of included studies were searched. STUDY SELECTION: Systematic reviews with 2 or more randomized controlled trials (RCTs) that focused on medical cannabinoids for pain, spasticity, or nausea and vomiting were included. For adverse events, any meta-analysis for the conditions listed or of adverse events of cannabinoids was included. SYNTHESIS: From 1085 articles, 31 relevant systematic reviews were identified including 23 for pain, 5 for spasticity, 6 for nausea and vomiting, and 12 for adverse events. Meta-analysis of 15 RCTs found more patients taking cannabinoids attained at least a 30% pain reduction: risk ratio (RR) of 1.37 (95% CI 1.14 to 1.64), number needed to treat (NNT) of 11. Sensitivity analysis found study size and duration affected findings (subgroup differences, P ≤ .03), with larger and longer RCTs finding no benefit. Meta-analysis of 4 RCTs found a positive global impression of change in spasticity (RR = 1.45, 95% CI 1.08 to 1.95, NNT = 7). Other results were not consistently statistically significant, but when positive, a 30% or more improvement in spasticity had an NNT of 10. Meta-analysis of 7 RCTs for control of nausea and vomiting after chemotherapy found an RR of 3.60 (95% CI 2.55 to 5.09) with an NNT of 3. Adverse effects caused more patients to stop treatment (number needed to harm [NNH] of 8 to 22). Individual adverse events were very common, including dizziness (NNH = 5), sedation (NNH = 5), confusion (NNH = 15), and dissociation (NNH = 20). "Feeling high" was reported in 35% to 70% of users. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) evaluation reduced evidence ratings of benefit to low or very low. CONCLUSION: There is reasonable evidence that cannabinoids improve nausea and vomiting after chemotherapy. They might improve spasticity (primarily in multiple sclerosis). There is some uncertainty about whether cannabinoids improve pain, but if they do, it is neuropathic pain and the benefit is likely small. Adverse effects are very common, meaning benefits would need to be considerable to warrant trials of therapy.

Effect of medication timing on anticoagulation stability in users of warfarin (the INRange RCT): study protocol for a randomized controlled trial.

BACKGROUND: Warfarin is an oral anticoagulant medication that disrupts the liver's production of clotting factors. While this medication is highly effective for the prevention of thromboembolic events, it also has a narrow therapeutic range and a vulnerability to interactions with other drugs and vitamin K-containing foods. Warfarin is commonly ingested at dinnertime, the same time of day that dietary vitamin K consumption (found largely in green leafy vegetables) is most variable. While the long half-life of warfarin might make this irrelevant, the ultra short half-life of vitamin K and the possibility of a hepatic first-pass effect for warfarin make it worth evaluating whether morning ingestion of warfarin, when vitamin K levels are consistently low, leads to greater stability of its anticoagulant effect. An examination of the timing of administration on the effectiveness of warfarin has never before been conducted. METHODS/DESIGN: This is a 7-month Prospective Randomized Open Blinded End-point (PROBE) study in which established evening warfarin users (primary care managed Canadian outpatients in the provinces of British Columbia and Alberta) will be randomized to either switch to morning ingestion of warfarin (the intervention) or to continue with evening use (the control). The primary outcome is the percent change in the proportion of time spent outside the therapeutic range of the international normalized ratio (INR) blood test. Secondary outcomes include change in proportion of time spent within the therapeutic INR range (TTR), percentage of patients with TTR >75 %, percentage of patients with TTR <60 %, and major warfarin-related cardiovascular events (including all-cause mortality, hospitalization for stroke, hospitalization for GI bleeding, and deep venous thrombosis/pulmonary embolism). We will also compare whether day-to-day variability in the consumption of high vitamin K-containing foods at baseline affects the baseline TTR in this cohort of evening warfarin users. DISCUSSION: This study addresses whether the timing of warfarin ingestion influences the stability of its anticoagulant effect. Should morning ingestion prove superior, the safety and effectiveness of this medication, and hence the prevention of stroke, pulmonary embolus, and major hemorrhage, could potentially be improved with no added cost or inconvenience to the patient. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02376803 . Registered on 25 February 2015.

Vitamin D: A Narrative Review Examining the Evidence for Ten Beliefs.

Over the past decade, a large body of observational evidence has suggested an association between lower vitamin D status (25-hydroxyvitamin D) and multiple acute and chronic disorders, including cancer, multiple sclerosis, depression and respiratory tract infections. This evidence has fostered the hypothesis that increasing vitamin D intake may treat and prevent such disorders. Our objective was to perform a critical analysis of the highest-level evidence for ten common beliefs regarding vitamin D for the prevention of falls, fractures and respiratory tract infections, the reduction of cancer incidence/mortality and overall mortality, and the prevention or treatment of depression/mental well-being, rheumatoid arthritis and multiple sclerosis, as well as maximum dosing and regular testing. We searched the Cochrane Database of Systematic Reviews and PubMed (up to August 2014) for randomized controlled trials and systematic reviews/meta-analyses based on those studies. All searches were performed, all evidence reviewed and each section written by at least two authors. The evidence shows that vitamin D supplementation provides some benefit in fracture prevention (likely ∼10-15 % relative reduction), particularly at a dose ≥800 IU and with calcium; a likely benefit in the rate of falls, though it is less clear whether the number of fallers changes; and a possible small (∼5 %) relative reduction in mortality. Evidence does not support the use of vitamin D supplementation for the prevention of cancer, respiratory infections or rheumatoid arthritis. Similarly, evidence does not support vitamin D supplementation for the treatment of multiple sclerosis and rheumatoid arthritis or for improving depression/mental well-being. Regular testing of 25-hydroxyvitamin D is generally not required, and mega-doses (≥300,000 IU) appear to increase harms. Much of the evidence is at high risk of bias, with multiple flaws, including analyses of secondary endpoints, small and underpowered studies, inconsistent results and numerous other issues. Therefore, enthusiasm for a vitamin D panacea should be tempered.